Mechanism for truing and dressing grinding wheels



' EDWARD n. coNNnns, or cINcINNA'rI, omo, AssIenonl mom'rancisron Tanni@ MACHINE AN-n Toor. coiarANY, cfr cmcmiva'rr, e.; npqnpamm0ngoma j f as einery wheels employed in machinery for .grinding or polishing the surfaces of metal 'Be it known that I, EDWARD iiiizcnamsm son raurivsnlvn nanssriie @BINDING .w .f e'

A Appiiaaon .inea october a7, i921., Serial no. 510,127.

To all whom it may concern.'

R. CoNNiiizs, a citizen of the United States, residing at Cincinnati, in the countyof Hamilton and State of Ohio, have invented certain new and useful Improvements in Mechanismfor Truing and Dressing Grinding Wheels, of-which the following is a specification. x

My invention relates to mechanism for truing and dressing grinding wheels, such in precision grinding. A usual means heretofore employed in truingand dressing operations on grinding wheels of this character has been a diamond tool comprising a diamond made to contact the inding surface of the grinding wheel, but diamonds have be-y come very scarce and'very expensive. It is the object of my inventionto provide means to dispense with the use of diamonds for these purposes. i

It is the object of my invention further to provide a rotary4 abrading part arranged t'o contactthe grinding surface of a grinding wheel in such manner as to cause rotation to be imparted to the rotary abradin 'part by closely associated with the rotary abrading part, whereby such rotation is maintaine during intervals between contacts between the rotary abrading part and the grinding wheel; and, further,to provide a structure of this character with novel meansl to present the rotary abrading part in various positions and at various angles to the rotary grinding wheel. l

Mypresent invention is an elaboration on the inventions shown, described and claimed in my copending applications for Letters Patent of the United States, for devices for 'truing and dressing grinding wheels, respectively, Serial No. 199,889, filed November 2, 1917, and Serial No. 366,970, filed March 18,' 1920, and for mechanisms :for truing and dressing grinding wheels, Serial No. 415,402,

filed October 7, 1920, and Serial No. 415,403, filed October 7, 1920, and issued respectively as Patents Nos. 1,395,391, 1,395,392, 1,395,- 393 and 1,395,394, dated November 1, 1921.

I have in the drawings exemplified my invention as employing a rotary abrading en- ,l cil and also as employing a rotary abra 'ng wheel, the invention 'being applicablev to either styles of lrotary abrading parts.

means,

2--2 of Fig. 3. Fig. 3 ,is a cross-section of-the same, taken in the plane of the line 3--3 of Fig. 2. Fig. 4 is an edge elevation of the clamping means. y

Fig. 5 represents an end elevation, exemplifying my improved. device `employing a rotary abrading wheel and employed in dressing a grinding wheel of a grinding machine, thelatter being partly broken away.

saine. Y

Fig. 7. is a cross-section of the same, taken on the line 7-7 of Fig. 6; and,

'abrading pencil in axial section on the line Fig. 6 is a plan view of a portion of the f Fig. 8 is a .front elevation of the same, with the rotary abrading wheel, chuck and iiy- -wheel in axial section on the line` 81-8 ofA My invention is intended for use directly on a so-. called grinding or olishing machine employing a rotary grin in or polishing wheel for effecting the grin' ing or polishing.

I have exemplified the work as cylindrical, although it may be' of other form, for instance, flat in the character ef'machine exemplied in my'application Serial No. 415,402, or any improved device may be employed in truing or dressing a grinding wheel while grinding'or polishing an inner cylindrical surface.

Referring to Figs. land 5, the essentials of a grinding oir polishing machine for polishing cylindrical surfaces'are shown. The frame is exemplified at 21, on which there is a support 22, a rotary grinding 'wheel .23 lbeing suitably journaled oli-this support, and suitably driven for rotating the same. A work-support 24 carries ausual head-stock 25 and a usual tail-stock, the axially adjustable sleeve 26 of the latter being shown. Relative feeding movement lengthwise'of the work is imparted between the sup ort of the rotary grinding wheel and the wor support.

lin some machines of this character the support for the grinding` wheel forms a carriage slidable on guideways 27 of the frame and has reciprocatin feeding movements lengthwise of the axis of rotation of theAv grinding Wheel imparted thereto by suitable means. ln-other machines of this character the Work-support forms a carriage slidable on guideways 28 of the frame, reciprocating feeding movements being imparted to the work-carriage in reverse directions lengthwise of the axis of rotation ofthe grinding wheel by suitable means. rlhe rinding wheel is usually on a slide 29, slida le in guideways 30 on the support 22 to adjust the grinding Wheel toward and from the work by suitable means. Such feeding andcontrol means therefor are for instance shown and described in my copending application Serial No. 199,889.

The work is represented as a heavy shaft 31, its connection with the tail-center being shown. -Rotation is imparted to the work by suitable means, for instance by means of a step-pulley 32, or as shown and described in my aforesaid application Serial No. 199,889.

rlhe rotation imparted to the grinding wheel is instanced as in the direction ofthe arrow a, while the rotation imparted to the work is instanced as in the direction of the arrow rThe direction of rotation of the rotary abrading part is in the direction of the arrow o.

rllhe grinding wheel will in course of time become impregnated with particles of dirt or metal from the work being -operated on and become comparatively glossy and thereby lose its grinding edect. rlihe grinding wheel may also in course of operation be` come out'of true, that is to say, its grinding periphery or grinding surface will be no longer a true cylinder, if a cylindrical grinding` surface is employed, or its granular structure will become dull.

By means of my invention the particles of dirt and metal are removed-from the inding wheel, and the recesses and pores in the grlnding surface of the rotary grinding wheel are cleared, and the particles of grains of .the grinding wheel are sharpened.

li Yhave in Figs. 1 to 3 inclusive exemplilied the rotary abrading part as a rotary abrading pencil 35 and in Figs. 5 to 8 inneeaeaa in dierent relations for accomplishing different degrees -ofl fineness of truing or dressing.-

When employing a rotary abrading pencil, a positioning of the rotary abrading pencil so that its axis oflrotation is proximate to a line'radial to the axis of rotation of the grinding wheel Iwill result in a dressing of the'grinding wheel with a liner sur face, whereas, if the rotary abrading pencil is positioned with its axis of rotation describing a chord to the circle of the grinding wheel, or'at an angle to the vertical plane perpendicular to the axis of rotation of the grinding wheel, the rinding surface will be trued or dressed wit ya coarser surface, the degree of coarseness dependingon the degree which the axis of rotation of the abrading pencil departs from a substantial radial position.

When employing a rotary abrading wheel a dressing of the grinding wheel with a finer surface is accomplished, when the axis of rotation -of the rotary abrading wheel approaches parallelism with the axis of rotation of the grinding wheel, whereas if the abrading wheel is placed at an angle with relation to the grinding wheel, the dressing of the grinding wheel will be coarser, the coarseness of dressing depending on the degree of angularity between the arts.

li-have found it desirable further to place the rotary abrading part as close to' the work as possible, and that in certain relations very little space is permitted in which to locate the rotary-abrading part. This is especially true in grinding inside surfaces. ll have therefore provided simple and extremely compact mechanism for locating the rotary abrading part and for maintainingthe rotations of the rotary vabrading part between intervals of contact with the rotating grinding wheel.

Thus li have provided a rotor 39, comprising a chuck 40 and a fly-wheel 4:1. rThe chuck may be of any desired form for holding the rotary abrading part either mediately or immediately. This chuck or holding device is exemplified as a solid chuck provided with a set-screw l2 for firmly securing the part received in the chuck in place. The part received in the chuck is in Figs. 1, 2 and 3 exemplified as the rotary abrading pencil 35, one end of which is secured in the chuck. rli`he rotary abrading pencil is exemplified as having an axial bore d3, the outer or abrading end of which is surrounded by a frusto-conical abrading face 4:4.

The abrading pencil employed may be such as is more fully shown and described in my copending application for Letters Patent of the lUnited States for abrading pencils, Serial No. A498,732, filed September 6, 1921. 'lhe abrading pencil is exemplified .I as haying a body,'the oli-which are of greater len ths than the diameter of its bore, and the ength of its body is exemplilfied as greater than the lengthsv of said radii.

The part received in the chuck is, in Figs. 5 to 8 linclusive, exemplied as a stem 47, onl which the rotary abrading wheel36 is secured by havin@r the reduced portion 48 of the stem received through an axial hole 49 of the abrading wheel, the abrading wheel y being clamped. between a shoulder 50 on the stem and a washer 51 ur d toward the shoulder by a nut 52 recelved over the threaded end 53 of the stern.V

A shank 55, is' abrading part. T isis shown comprising a stem 56 and a sleeve 57 received there` about. The sleeve is provided with a reduced portion 58,- about which ball-bearings 59, 60, are received. The outer .end .0f the stem `is provided with' an annular flange 64. The reduced portion of the 1 'by the rotating grinding wheel, which is exemplified as the sole means for rotating the rotary` abrading part.

The fly-wheel is so proportioned with relation to therotary abrading part that the inertiav of rotation offthe .fly-wheel is.y

greater thanthe inertia of rotation of-the rotary abrading part. The ily-wheel 1s preferably heavier than the rotary abrading" part, `regardless of whether the. rotary abrading part be arotary abrading lpencil or a rotary abrading' wheel; lThe fly-wheel is preferably composed of a suitable metal. In practice high speeds of rotation are imparted to the ly-wheelbyncontact of the rotary abrading part with the grinding surface of the rotating grinding wheel.

Rotation of the rotary abrading part is' by this arrangement maintained for considerable periods of time between contacts betweenthe grinding wheel and the rotary abrading part, so as to maintain momentum of rotation of the rotary abrading part with suflicient speed and force to act upon 'the grinding wheel with a rotating abrading efect as soon as contact isA made .therewith in the axial reciprocations of the grinding wheel.

The ily-wheel is provided with a recess 72 having an annu ar shoulder 73. The ball-bearings are receivedin said recess, the outer ball-races 74, 75,.being squeezed within the annular wall of said recess for aiding in positioning the same. The outer ball-race rovided for the rotary 74 received against said shoulder.,vr The' outer ball-races are preferably separated by y a washer ,The opposite end of the stem is threaded as at 81, for receivinga nut 82, whichvbears' a ainst the opposite end of the sleeve, for ajustin the ease of operation ,of'theball-bearings and to take up any wear therein. There is a lspace 83 between the end of the sleeve and the flange 64 on .the stem 56 to permit such adjustment. A jam-nut 84 is provided to lock the parts in adjusted posi'- tlons.

Afclosing plate 85 has its peripherylrethe. stem and 'the sleeve in opposite axia directions, and thereby'adjustmg ceived in an annular rabbet 86 in the ind ner end of said fly-wheel and is secured` in place, as by means of screws 87,'received through 'said plate and into the ily-wheel.

The ball-bearingsv are preferably Vcombined end-,thrust and radial ball-bearings',

so arranged that endthrust resistance is imparted to the rotary. abrading part to definitely retain the rotary abrading: part inits correct path of travel. The fly-wheel has the chuck intimately connected therewith and the 'fly-wheel is closely adjacent.

to the chuck, sov that the operative parts are closely related and occupy little space for .being received in rsmall space .in the grinding machine. The chuck and fly-wheel are shown integral with each other, whereby compactness of parts and steadiness of rotation of the rotaryabradingv part are. insured.

When an abrading wheel is "employed, 4

the axis of the stem 47 is preferably pre` sented lengthwise of the axis ,of rotation of the grinding wheel, and when' a rotary abrading pencil is emplo ed its axis ofretation 1s presentedv en wise toward the grinding wheel.

A clamp 91 is arranged to be received about the shank 55, the clamp being shown inthe form of va stem 92, from which the jaws of the clamp extend, a bolt 93 being l provided vor'clamping the clamp about the shank 55 in desired adjusted position lengthwise of the shank 55. The bolt isjournaled in one of the jaws and is threaded in the other jaw of the chuck.l

A clamp 95 is arran ed to be received y about the tail-center,an is shown .comprising a jaw 96 having an inner recess 97 and an arm 98, in which latter a set-screw 99 is threaded. The set-screw is arranged to l impinge the tail-center and clamp the tailcenter between it and the converging walls of the jaw. Y

An adjustable connection is shown between the stem 92, the recessed bearing being on a stem 104 extending from the jaw 96 and arranged to be 'clamped about the ball bybolts 105,' when the shank .of the rotary abrading part has been adjusted to proper'.

position forv presenting the abrading wheel or. the abrading pencil in. properrelation to the grinding wheel.

rThe clamp 95 may be adjusted'about the' axis of a tail-spindld` and clamped in adjusted relation. rlihe shank which supports the abradingxpart is arranged to be axially adjusted in the clamp 91 and clamped in adjusted positions. The joint between Vthe two clamps permitsthe tilting of the shank 55 and turning of the` shank with relation to its'support. lAdjustments of the abrad ing wheel and of the abrading pencil to by Letters Patent, is:

accommodate any desired conditions' may therefore be made, so as to causeproper coaction between the"rotary abrading part and the grinding wheel,y for ecting any desired tineness or coarseness of truing or dressing eiect upon the grinding wheel, by simple, compact, durable and readily adjustable means. y 'j Having thus fully described my. invention, what li claim asnew, and desire to secure 1. lin mechanism for truing and 'dressing grinding wheels'g'the combination of :a normally quiescent rotary abrading partmeans for positioning the latter with relation 'to a rotatable 'grinding wheel, and a" fly-wheel for said rotary abrading part,.said positioning means located at one snide of both said rotary abrading part and said fly-wheel.

2. lin mechanism'tfor truing and-dressing vgrinding wheels, the combination o .rotatable means for rotatively securing `rotary abrading parts respectively having an end abrading face andy a peripheral abrading face, saidrotary abrading parts being normally quiescent and a support for said rotatable meanscomprising means for attaching said support to a machinel part and a joint between said attaching means'and said rotatable means arranged for adjusting said rotatable means topositi'on the axes of rotation of said rotary abrading parts selectively' lengthwise of and crosswise of the v'axis ot rotation of a rotatable grinding wheel whbse axis of rotation is maintained in'tconstant directlon.

v3. lin mechanismvfor'truing and dressingy grinding wheels, the combination of a rotary securing means for rotary abrading parts respectively having an end abrading tace and f Macnee a peripheral abrading face presented with theiraxes of rotation selectively substantially parallel with and at substantial ri ht angles to the axis ot rotation ot a rotata le grinding wheel whose axis of rotation is maintained in constant direction, said rotary abrading parts being normally quiescent, and supporting means :tor said rotary securing means comprising an attaching part for attaching the same to a machine part and a universal joint between said attaching part and said rotary securing means.

4f. ln mechanism for truing and dressing grinding wheels, the combination of a supporting means, and a rotor comprising an associated chuck and fly-wheel at one end of said supporting means, said chuck arranged for supporting a rotary abrading part.

5. lin mechanism for truing and dressing grinding wheels, the combination of a shank, a tty-wheel at one end of said shank, a ballbearing between said last-named end of said 'shank and said fly-wheel, and a chuck integral with said fly-wheel, said chuck arranged or securing a rotary abrading part.

6. lin mechanism for truing and dressing grinding wheels, the combination of a shank, a rotor comprising a chuck and a y-wheel, and radial and end-thrust ball-bearings between one end of said shank and said rotor arranged for controlling thrusts of said rotor in opposite directions lengthwise ot the axis of rotation of said rotor, said chuck arranged for securing a rotary abrading part.

7. lin mechanism for truing and dressing grinding wheels, the combination oit a shank comprising a plurality of telescoping parts, com ined radial and end-thrust ball-bearings about said telescoping parts at one end of said shank, said telescoping parts having contact-faces thereon for said ball-bearings, means for adjustingsaid telescoping parts in opposite directions for adjusting said ball-bearings, and a rotor comprising a chuck and a fly-wheel received about said ball-bearings and havingfconnection therewith for rotation ot said rotor upon said shank, said chuck arranged for securing a rotary abrading part thereto.

lin testimony whereof, li have hereunto signed my name in the presence of two subscribing witnesses.

EDWARD lit. CONNERS. lin presence ot Deiana WnRNsrNG, J. Knauer.

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